From 2cf44da3018969475fabf2fa2deba99a85e2be8b Mon Sep 17 00:00:00 2001
From: Caleb Connolly <caleb@postmarketos.org>
Date: Thu, 13 Jun 2024 05:57:38 +0200
Subject: [PATCH] meta: cache: rework cache clear (MR 2252)

This makes a looot more sense. Add a disable method too for use in
tests.

Signed-off-by: Caleb Connolly <caleb@postmarketos.org>
---
 pmb/chroot/zap.py    |  4 ++--
 pmb/helpers/file.py  |  2 +-
 pmb/meta/__init__.py | 38 ++++++++------------------------------
 3 files changed, 11 insertions(+), 33 deletions(-)

diff --git a/pmb/chroot/zap.py b/pmb/chroot/zap.py
index f3cc6240..8f61c374 100644
--- a/pmb/chroot/zap.py
+++ b/pmb/chroot/zap.py
@@ -79,9 +79,9 @@ def zap(confirm=True, dry=False, pkgs_local=False, http=False,
     pmb.config.workdir.clean()
 
     # Chroots were zapped, so no repo lists exist anymore
-    Cache.clear_cache(pmb.chroot.apk.update_repository_list)
+    pmb.chroot.apk.update_repository_list.cache_clear()
     # Let chroot.init be called again
-    Cache.clear_cache(pmb.chroot.init)
+    pmb.chroot.init.cache_clear()
 
     # Print amount of cleaned up space
     if dry:
diff --git a/pmb/helpers/file.py b/pmb/helpers/file.py
index eae9307b..dc0527ba 100644
--- a/pmb/helpers/file.py
+++ b/pmb/helpers/file.py
@@ -47,7 +47,7 @@ def replace_apkbuild(args: PmbArgs, pkgname, key, new, in_quotes=False):
     replace(path, "\n" + line_old + "\n", "\n" + line_new + "\n")
 
     # Verify
-    Cache.clear_cache(pmb.parse.apkbuild)
+    pmb.parse.apkbuild.cache_clear()
     apkbuild = pmb.parse.apkbuild(path)
     if apkbuild[key] != str(new):
         raise RuntimeError("Failed to set '{}' for pmaport '{}'. Make sure"
diff --git a/pmb/meta/__init__.py b/pmb/meta/__init__.py
index a6272179..88262b39 100644
--- a/pmb/meta/__init__.py
+++ b/pmb/meta/__init__.py
@@ -9,9 +9,9 @@ class Wrapper:
     def __init__(self, cache: "Cache", func: Callable):
         self.cache = cache
         self.func = func
+        self.disabled = False
         self.__module__ = func.__module__
         self.__name__ = func.__name__
-        self.fhash = hash(func)
 
 
     # When someone attempts to call a cached function, they'll
@@ -19,13 +19,14 @@ class Wrapper:
     # result and if not then we do the actual function call and
     # cache it if applicable
     def __call__(self, *args, **kwargs):
-        #print(f"Cache.wrapper({args}, {kwargs})")
+        if self.disabled:
+            return self.func(*args, **kwargs)
+
         # Build the cache key from the function arguments that we
         # care about, which might be none of them
         key = self.cache.build_key(self.func, *args, **kwargs)
         # Don't cache
         if key is None:
-            # print(f"Cache: {func.__name__} NULL key!")
             return self.func(*args, **kwargs)
 
         if key not in self.cache.cache:
@@ -39,14 +40,11 @@ class Wrapper:
         #print(f"Cache: {func.__name__}({key})")
         return self.cache.cache[key]
 
+    def cache_clear(self):
+        self.cache.clear()
 
-    # This is a hacky workaround to let us fetch the hash of the
-    # underlying function, since hash(cached_func()) would just get
-    # the hash of the wrapper
-    def __getattribute__(self, name: str):
-        if name == "@realhash":
-            return self.fhash
-        return super(Wrapper, self).__getattribute__(name)
+    def cache_disable(self):
+        self.disabled = True
 
 
 class Cache:
@@ -56,7 +54,6 @@ class Cache:
     :param kwargs: these are arguments where we should only cache if the
     function is called with the given value. For example, in pmb.build._package
     we never want to use the cached result when called with force=True."""
-    _cache: Dict[int, "Cache"] = {}
 
     def __init__(self, *args, cache_deepcopy=False, **kwargs):
         for a in args:
@@ -66,7 +63,6 @@ class Cache:
         if len(args) != len(set(args)):
             raise ValueError("Duplicate cache key properties")
 
-        # print(f"Cache.__init__({args})")
         self.cache = {}
         self.params = args
         self.kwargs = kwargs
@@ -81,7 +77,6 @@ class Cache:
         if not self.params and not self.kwargs:
             return key
 
-        #print(f"Cache.build_key({func}, {args}, {kwargs})")
         argnames = list(func.__code__.co_varnames)[:func.__code__.co_argcount]
 
         # Build a dictionary of the arguments passed to the function and their values
@@ -127,10 +122,6 @@ class Cache:
 
 
     def __call__(self, func: Callable):
-        fhash = hash(func)
-        Cache._cache[fhash] = self
-        # print(f"Cache: {func.__module__}.{func.__name__} hash {fhash}")
-        # print(f"Cache.__call__({func})")
         argnames = func.__code__.co_varnames
         for a in self.params:
             if a not in argnames:
@@ -141,16 +132,3 @@ class Cache:
 
     def clear(self):
         self.cache.clear()
-
-
-    @staticmethod
-    def clear_cache(func: Callable):
-        key = None
-        try:
-            key = getattr(func, "@realhash")
-        except AttributeError:
-            return
-        cache = getattr(Cache, "_cache")
-        if key not in cache:
-            return
-        cache[key].clear()